I got a new tv and my Apple TV has a max setting of 1080p @ 60hz. My TV is 120hz. Do I have a concern?

No. You can't tell the different between 60 Hz and 120 Hz because movies are 24 fps. 60 Hz refers to the screen being able to refresh the entire screen 60 times per second (times per second = Hertz = Hz). Most, but not all, TV programming doesn't go above 60 Hz anyway.

The only reason for higher Hz is 3D or if you have access to content that is.

No. You can't tell the different between 60 Hz and 120 Hz because movies are 24 fps. 60 Hz refers to the screen being able to refresh the entire screen 60 times per second (times per second = Hertz = Hz). Most, but not all, TV programming doesn't go above 60 Hz anyway.

The only reason for higher Hz is 3D or if you have access to content that is.

This is not entirely true. Every source regardless of what you are playing is going to be in 24p when it comes to movies. Even TV shows are generally displayed in 60i or 30p within the US, and internationally they are almost always in 50i. 120hz TV's interpolate (guess) data to make it a 120hz output on the panel.

Either way you have no need for concern, because while the source is 60hz, your TV will interpolate the frames to make it 120hz on the display itself. If all that mattered were the source frames, 120hz (or 240hz) TVs wouldn't exist at all, as there would never be a format that could play properly on it.

And for the record, 99% of the population can tell a difference between 60hz and 120hz (120 to 240 is debatable). Go into a Best Buy and look at them side by side and I guarantee you will be able to see the judder reduction on the display.

I'm one of those people who don't like the upscaling to 120Hz/240Hz. When I went looking for my latest TV, I specifically looked for a 60Hz one only. It took a bit of searching, but I found a nice LG 46" 60Hz at ABC Warehouse. I couldn't be happier with it.

the aTV is constantly putting out 60 Fps, i've seem complaints about that, since most movies are in 24

Actually, it is technically constantly putting out 30 fps at 60hz (each frame is displayed twice). The only things that put out 60fps at the source are HD cable boxes (720p only, not 1080i), and only if 60fps is supported by the respective channel. The only channels that support 720p/60 are ABC, FOX, ESPN, and their subsidiaries. NBC, CBS, and every other HD broadcaster (in the USA at least) use 1080i/30, which is technically a better format for most viewings, but worse for sports and fast motion pictures.